Known as a method of cutting an object to be processed by laser processing is one disclosed in the following Nonpatent Document 1. The laser processing method disclosed in Nonpatent Document 1 is one for cutting a silicon wafer, which uses laser light having a wavelength near 1 μm transmittable through silicon and converges this laser light within the wafer, so as to continuously form a modified layer, from which the wafer is cut.
Nonpatent Document 1: Arai, Kazuhisa, “Laser dicing process for Si wafer”, Journal of the Japan Society for Abrasive Technology, Vol. 47, No. 5, May, 2003, 229-231.